In conveying and sorting packages, diverter swing arms (also known as diverter blades or paddles) are used to divert an article from a conveying surface onto another conveying surface or some form of discharge chute for further downstream collating and sorting. Diverter swing arms are thus important in sorting articles in an accurate and timely manner.
For example, as shown in FIG. 1, articles (which are generally indicated by reference numeral 100) are traveling along a conveying surface 102. The diverter swing arm 110 is mounted for rotation with respect to the conveying surface 102, so that the diverter swing arm 110 can be selectively rotated by an actuator 112 into the pathway of a particular article to engage and divert that particular article from the conveying surface 102. In the example shown in FIG. 1, the article is diverted onto a discharge chute 104.
Because such diverter swing arms are used where there is a significant volume of articles being conveyed, a common diverter swing arm must often perform a complete cycle (i.e., rotate and engage the article, and then return to a home position) in fractions of a second. For example, in some implementations, the swing arm may cycle at speeds in excess of one-quarter second. At the same time, such diverter swing arms may need to push an article having a weight of up to 70 lbs (or more). Accordingly, it is important that such diverter swing arms be very durable and reliable.
In many cases, such diverter swing arms are made of steel. Such all-metal diverter swing arms often fall victim to metal fatigue, which eventually causes fracture and failure.
U.S. Pat. No. 5,918,724 (which is incorporated herein by reference) describes and claims a diverter blade that includes an inner metallic section (or skeleton) and an outer plastic section. The metallic section is adapted to be connected to a drive motor. As such, the metallic section includes a rotary mounting portion defining an axis of rotation, and at least one torque-transmitting member (i.e., a linkage arm) projecting from the mounting portion. The plastic section is molded over and envelopes the metallic section, and the plastic section includes a front wall that is adapted to engage articles on the conveying surface. However, such a two-material diverter blade still has a metal linkage arm that is prone to metal fatigue, which again eventually causes fracture and failure.